{"doi":"10.3389/fcvm.2021.772815","title":"Cardiorespiratory Responses During High-Intensity Interval Training Prescribed by Rating of Perceived Exertion in Patients After Myocardial Infarction Enrolled in Early Outpatient Cardiac Rehabilitation","abstract":"Objective: We aimed to determine the cardiorespiratory responses during, and adaptations to, high-intensity interval training (HIIT) prescribed using ratings of perceived exertion (RPE) in patients after myocardial infarction (MI) during early outpatient cardiac rehabilitation (CR). Methods: We prospectively recruited 29 MI patients after percutaneous coronary intervention who began CR within 2 weeks after hospital discharge. Eleven patients (seven men; four women; age: 61 ± 11 yrs) who completed ≥24 supervised HIIT sessions with metabolic gas exchange measured during HIIT once weekly for 8 weeks and performed pre- and post- CR cardiopulmonary exercise tests were included in the study. Each HIIT session consisted of 5–8 high-intensity intervals [HIIs, 1-min RPE 14–17 (Borg 6–20 scale)] and low-intensity intervals (LIIs, 4-min RPE &amp;lt; 12). Metabolic gas exchange, heart rate (HR), and blood pressure during HIIT were measured. Results: The mean oxygen uptake ( <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2 ) during HIIs across 88 sessions of HIITs [91 (14)% of <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2peak , median (interquartile range, IQR)] was significantly higher than the lower limit of target <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2 zone (75% of <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2peak ) recommended for the HII ( p &amp;lt; 0.001). Exercise intensity during RPE-prescribed HIITs, determined as % <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M5\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2peak , was highly repeatable with intra-class correlations of 0.95 (95% CI 0.86– 0.99, p &amp;lt; 0.001). For cardiorespiratory adaptations from the first to the last session of HIIT, treadmill speed, treadmill grade, treadmill power, <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M6\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2HII , % <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M7\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2peak , and V E during HIIs were increased (all p &amp;lt; 0.05), while no difference was found for HR, %HR peak and systolic blood pressure (all p &amp;gt; 0.05). <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M8\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2peak increased by an average of 9% from pre-CR to post-CR. No adverse events occurred. Conclusion: Our results demonstrate that HIIT can be effectively prescribed using RPE in MI patients during early outpatient CR. Participation in RPE-prescribed HIIT increases exercise workload and <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M9\"><mml:mrow><mml:mover accent=\"true\"><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover><mml:mtext>O</mml:mtext></mml:mrow></mml:math> 2 during exercise training without increased perception of effort or excessive increases in heart rate or blood pressure.","journal":"Frontiers in Cardiovascular Medicine","year":2022,"id":281916,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9178,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":753557,"name":"Shane M. Hammer","orcid":"0000-0003-1937-294X","position":1,"is_corresponding":false},{"id":399837,"name":"Joshua R. Smith","orcid":"0000-0002-3687-6261","position":2,"is_corresponding":false},{"id":958045,"name":"Mary C. MacGillivray","orcid":null,"position":3,"is_corresponding":false},{"id":958046,"name":"Benjamin Simmons","orcid":null,"position":4,"is_corresponding":false},{"id":479727,"name":"Ray W. Squires","orcid":"0000-0002-4827-7098","position":5,"is_corresponding":false},{"id":957565,"name":"Suixin Liu","orcid":"0000-0001-7621-0096","position":6,"is_corresponding":false},{"id":393526,"name":"Thomas P. Olson","orcid":"0000-0002-3446-0414","position":7,"is_corresponding":false},{"id":957564,"name":"Yaoshan Dun","orcid":"0000-0001-8642-9024","position":0,"is_corresponding":true}],"reference_count":29,"raw_metadata":null,"created_at":"2026-07-19T00:29:15.734856Z","pmid":"35071350","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}